An ordinary cylinder used to hold a gas under pressure may include a threaded socket inlet which leads to a check valve that is held in closed position by the pressure of the gas inside the cylinder.
Whenever a gas cylinder is to be charged with gas under pressure, it is necessary to tightly screw a fitting into or on a threaded socket inlet of the gas cylinder in order to connect the gas cylinder inlet to a supply of gas under pressure. The operation of screwing a fitting into the threaded socket inlet of a gas cylinder is time-consuming and therefore un-desirable when filling a large number of gas cylinders in a manufacturing plant or at a refilling station. For example, two steps of operation are required to make a connection with most couplers, which substantially increases the time and cost of cylinder refilling. Moreover, the repetitive motion of twisting the wrist can lead to carpal-tunnel syndrome or the like, which can be detrimental to the operators of a refilling station.
Although rapid-connect couplers exist for filling a gas cylinder, these couplers are deficient because they fail to consistently provide an airtight seal with the cylinder. Accordingly, filling gas cylinders can be inefficient because of the time it takes to properly seat the coupler, and the fact that improper seating often goes unnoticed, which also results in wasted time.
Additionally, existing rapid-connect couplers are also deficient because they are typically unable to adapt to more than one type of socket inlet. For example, some socket inlets may have a check valve which must be actuated for gas to flow through the valve, and such a check valve may be located in various locations and be associated with various diameters of inlet channels. Other socket inlets may not have a check valve. Existing rapid-connect couplers are not able couple with many types of inlets and are not re-configurable. A new coupler is typically required for each type of inlet.